<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .flex {
            position: relative;
        }
        .flex::before{
            content: " ";
            display: inline-block;
            height: 100%;
            width: 1%;
            vertical-align: middle;
        }
     
        .sub-flex{
            display: inline-block;
            vertical-align: middle;
        }
        /* table table-cell 布局 */
        .box{
            width: 100%;
            position: relative;
        }
        .left{
            position: absolute;
            left: 0;
            width: 300px;
            background-color: orange;

        }
        .right{
            position: absolute;
            right: 0;
            width: 300px;
            background-color: aqua;
        }
        .center{
            margin: 0 300px;
            background-color: #ff0;
        }
    
    </style>
</head>

<body>
    <!-- <div class="box flex">
        <div class="sub-flex">这是一个居中对齐</div>
    </div> -->
        <div class="box">
            <div class="left">left</div>
            <div class="right">right</div>
            <div class="center">center</div>
        </div>
        
    <script src="./index.js"></script>
    <!-- <script src="dist/babel-browser-build.js"></script>
    <script src="dist/browser-es-module-loader.js"></script> -->
    <script type="module">
        import { foo, age } from './es_module.js'
        console.log(foo)
    </script>
</body>

</html>